Chitosan antimicrobial activity

Campaniello, D., Bevilacqua, A., Sinigaglia, M. Corbo, M. R. (2008). Chitosan antimicrobial activity and potential applications for preserving minimally processed strawberries. Food Microbiology, 25(8), 992-1000. 

Peculiar characteristics of chitins and chitosans are hemostatic action, anti-inflammatory effect, biodegradability, biocompatibihty, besides antimicrobial activity, retention of growth factors, release of glucosamine and M-acetylglucosamine monomers and oligomers, and stimulation of cellular activities [11,12,295-297]. 

A number of important papers could not be cited in this chapter, due to the length limitations and the specific target of the chapter. For example, the antimicrobial activity of chitosans [349], the chitinolytic enzymes, the preparation of cosmetics, and the occurrence of chitin in fungi [350] are some of the subjects not dealt with specifically here, notwithstanding their importance. 

Many studies have been conducted on the antimicrobial activity of chitosan since Allan and Hadwiger (1979) first reported that chitosan and its derivatives had broad-spectrum antimicrobial effects. The group of researches proved that chitosans are capable of inhibiting the growth of some microorganisms including bacteria, yeasts, and fungi. 

Park, P. J., Je, J. Y., Byun, H. G., Moon, S. H., and Kim, S. K. (2004b). Antimicrobial activity of hetero-chitosans and their oligosaccharides with different molecular weights. ]. Microbiol. Biotechnol. 14,317-323. 

For other polysaccharides such as chitosan a high antimicrobial activity has been described - mainly against Escherichia coli and Staphylococcus aureus [153,154]. This activity of chitosan is the basis for the development of materials for wound healing, e.g., in combination with N,0-(carboxymethyl)chitosan and collagen [155]. 

Rhim, J.-W., Hong, S.-I., Park, H.-W., and Ng, P. K. W. (2006). Preparation and characterization of chitosan-based nanocomposite films with antimicrobial activity. J. Agric. Food Chem. 54,5814-5822. 

The organic acids, sorbic, benzoic, and propionic acids, and anhy-drates have been proposed and tested for antimicrobial activity in edible films. Organic acids are also being applied as an edible film, together with essential oils, into a chitosan matrix (Ouattara et al., 2000). From here they are initially released quickly (with the high gradient of ion concentration between the inside of a polymer matrix and the environment) but more... 

A water soluble quaternary ammonium derivative of chitosan (N-(2-hydroxy)propy 1-3 -trimethylammonium chitosan chloride, HTCC) was used as an antimicrobial agent for cotton fabrics. HTCC had a lower minimum inhibition concentration against Staphylococcus aureirs, Klebsiella pneumoiniae and Escherichia coU compared with that of chitosan, but the antimicrobial activity was lost on laundering. However, when cotton fabrics were treated simultaneously with HTCC and polycarboxylic acids (particularly butanetetracarboxylic acid) (BTCA),... 

The basic types of antinucrobial food packaging films are outlined and additives used in antimicrobial materials are discussed, with particular reference to potassium soibate, nisin, imazalil, allyl isothiocyanate and triclosan. The production of antimicrobial films by modification of the polymer chain itself is also mentioned and the natural antimicrobial activity of chitosan is considered. 17 refs. 

Journal of AppUed Polymer Science 80, No.13,24th June 2001, p.2495-501 MOLECULAR WEIGHT EFFECT ON ANTIMICROBIAL ACTIVITY OF CHITOSAN TREATED COTTON FABRICS Shin Y Yoo D I Jang J Chonnam,National University... 

Tsai et al. (2002) studied the effects of DD and preparation methods for chitin and chitosan on their antimicrobial activity. It was found that chemically (ch-chitin) and microbiologically prepared chitin (MO-chitin) could undergo further chemical deacetylation to produce chitosan with different DDs. However, MO-chitin that was deacetylated by various proteases had no antimicrobial activity (Tsai et al., 2002). However, for chitosan, as the DD increased, its antimicrobial effect on bacteria increased, even to a greater extent than that on fungi. 

Tsai, G.J., Su, W.-H., Chen, H.C., and Pan, C.-L. 2002. Antimicrobial activity of shrimp chitin and chitosan from different treatments and applications of fish preservation. Fisheries Sci. 68, 170-177. 

Yalpani, M., Johnson, F., and Robinson, L.E. 1992. Antimicrobial activity of some chitosan derivatives. In Advances in Chitin and Chitosan (C J. Brine, P.A. Sandford, and J.P. Zikakis, eds), pp. 543-555. Elsevier Applied Science, London, UK. 

Currently, researchers are trying to increase the low antimicrobial activity of chitosan to compare with commercially used chemicals. The recent advances include the use of composites and other biologically active substances (Table 3.3) that are known antimicrobial agents. The expected outcome is an increased antimicrobial effect due to the synergistic action of both antimicrobial agents. Moreover, the use of lesser synthetic agents to improve the naturally-derived polymer can be both economical and attractive. 

Metal ions. Chitosan is known to complex metal ions. The chelating ability of chitosan is superior compared to other known biopolymers [30]. This property is widely investigated for its use as sensors or filtration materials in heavy metal ion detection or separation [17, 20a, 31]. The binding of chitosan with metal ions is thought to provide donor atoms that may improve the antimicrobial activity of the material however, studies on this area are quite limited [32]. 

The most common biopolymers derived from animals are chitin and chito-san. Chitin is a macromolecule found in the shells of crabs, lobsters, shrimps, and insects. The primary unit in the chitin polymer is 2-deoxy-2-(acetylamino) glucose. Chitin can be degraded by chitinase. Chitosan is a modified natural carbohydrate polymer derived from deactylation of chitin, which occurs principally in animals of the phylum Arthropoda. Chitosan is also prepared from squid pens. Chitin is insoluble in its native form but chitosan, the partly deacetylated form, is water soluble. The materials are biocompatible and have antimicrobial activities as well as the ability to absorb heavy metal ions [16]. 

Hyaluronic acid is a linear polysaccharide formed from disaccharide units containing N-acetyl-D-glucosamine and glucuronic acid. Since it is present in almost all biological fluids and tissues, hyaluronic acid-based materials are very useful in biomedical applications. After cellulose, chitin is the second most abundant natural polysaccharide resource on earth. Chitin and its de-acetylated derivative chitosan are natural polymers composed of N-acetylglucosamine and glucosamine. Both chitin and chitosan have excellent properties such as biodegradability, biocompatibility, non-toxicity, hemostatic activity and antimicrobial activity. Chitin and its derivatives are widely used in various fields of medicine. 

Zheng L Y, Zhu J E (2003). Study on antimicrobial activity of chitosan with different molecular weights. Carbohyd. Polym. 54 527-530. 

Sugar-lectin specific interaction is an important cellular phenomenon. Li et al. [64] linked L-fucose to chitosan, which can act as a somatic agglutinin to induce bacteria aggregation. The enhanced antimicrobial activity of chitosan-L-fucose is attributed to the specific recognition and binding of the L-fucose moiety with PA-Il lectin on Pseudomonas aeruginosa surface. 

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